Projection exposure system

Abstract

A projection exposure system includes a light transmitting member located between a light source and fly's eye lens to receive most of the incident light and to transmit the incident light to the periphery of the fly's eye lens. Light transmission of the system may be carried out by a light pipe and conic reflection mirror concentrically placed therein, or by an optical fiber flux having a light entrance pupil consisting of a bundle of individual units and a ramified light exit pupil. The system has high light-utilizing efficiency and reduced exposure time because most of the incident light is used.

What is claimed is: 
     
       1. A projection exposure system comprising: a light source for producing light;   transformed illumination means for forming a transformed illumination, said transformed illumination means including a light transmitting member for performing tilted illumination to provide tilted illuminated light, said light transmitting member including a light entrance pupil and a light exit pupil;   a fly's eye lens that receives said tilted illuminated light and diverges said tilted illuminated light to provide diverging tilted illuminated light;   a mask that receives said diverging tilted illuminated light.   
     
     
       2. A projection exposure system according to claim 1, wherein said light transmitting member is an optical fiber flux in which said light entrance pupil includes a bundle of individual units and said light exit pupil is divided into a plurality of predetermined shapes according to patterns of transformed illumination. 
     
     
       3. A projection exposure system according to claim 2, wherein said light exit pupil of said optical fiber flux is split into a multitude of individual units to provide four-point illumination. 
     
     
       4. A projection exposure system according to claim 2, wherein said light exit pupil of said optical fiber flux is annular in shape to thereby perform annular illumination. 
     
     
       5. A projection exposure system according to claim 2, wherein said optical fiber flux is made of silica glass to transmit deep UV light. 
     
     
       6. A projection exposure system according to claim 1, further comprising a condenser lens for focussing said diverging tilted illuminated light to produce condensed light for reception by said mask. 
     
     
       7. A projection exposure system according to claim 1, wherein an inner surface of said light pipe is about 40-50 mm in diameter and a length of said light pipe is about 150 mm. 
     
     
       8. A projection exposure system comprising: a light source for producing light;   transformed illumination means for forming a transformed illumination, said transformed illumination means including a light transmitting member for performing tilted illumination to provide tilted illuminated light, said light transmitting member comprising: a light pipe having a light entrance pupil and a light exit pupil, and   a conic reflection mirror concentrically disposed in said light pipe having an apex directed toward said light source, said conic reflection mirror having a bottom diameter that is smaller than an inner diameter of said light exit pupil;     a fly's eye lens that receives said tilted illuminated light and diverges said tilted illuminated light to provide diverging tilted illuminated light; and   a mask that receives said diverging tilted illuminated light.   
     
     
       9. A projection exposure system according to claim 8, wherein an inner surface of said light pipe and an external surface of said conic reflection mirror are each reflective. 
     
     
       10. A projection exposure system according to claim 9, wherein said inner surface of said light pipe and said external surface of said conic reflection mirror are inclined to reflect said light perpendicularly. 
     
     
       11. A projection exposure system according to claim 8, wherein said conic reflection mirror is adaptable to move in an axial direction. 
     
     
       12. A projection exposure system according to claim 8, wherein said bottom diameter of said conic reflection mirror is about two thirds said inner diameter of said light exit pupil of said light pipe. 
     
     
       13. A projection exposure system according to claim 8, further comprising a condenser lens for focussing said diverging tilted illuminated light to produce condensed light for reception by said mask. 
     
     
       14. A projection exposure system according to claim 9, wherein said reflective surfaces are provided by an aluminum film. 
     
     
       15. A projection exposure system according to claim 10, wherein said inclined inner surface of said light pipe is parallel with said external surface of said conic reflection mirror. 
     
     
       16. A projection exposure system according to claim 9, wherein said inner surface of said light pipe is parallel to said produced light and said external surface of said conic reflection mirror is inclined to reflect said produced light toward said inner surface of said light pipe. 
     
     
       17. A projection exposure system according to claim 16, wherein a length of said conic reflection mirror is shorter than a length of said light pipe. 
     
     
       18. A projection exposure system according to claim 17, wherein said length of said conic reflection mirror is 90% of said length of said light pipe. 
     
     
       19. A projection exposure system comprising: a light source for producing light;   transformed illumination means for forming a transformed illumination, said transformed illumination means including a light transmitting member for performing tilted illumination to provide tilted illuminated light, said light transmitting member including a light entrance pupil and a light exit pupil;   a fly's eye lens that receives said tilted illuminated light and diverges said tilted illuminated light to provide diverging tilted illuminated light;   a condenser lens that receives and focuses said diverging tilted illuminated light to produce condensed light.   
     
     
       20. A projection exposure system comprising: a light source for producing light;   transformed illumination means for forming a transformed illumination, said transformed illumination means including a light transmitting member for performing tilted illumination to provide tilted illuminated light, said light transmitting member comprising: a light pipe having a light entrance pupil and a light exit pupil, and   a conic reflection mirror concentrically disposed in said light pipe having an apex directed toward said light source, said conic reflection mirror having a bottom diameter that is smaller than an inner diameter of said light exit pupil;     a fly's eye lens that receives said tilted illuminated light and diverges said tilted illuminated light to provide diverging tilted illuminated light; and   a condenser lens that receives and focuses said diverging tilted illuminated light to produce condensed light.